1. Field of the Invention
The present invention relates to an electric field coupler, a communication apparatus, a communication system, and a fabrication method for an electric field coupler.
2. Description of the Related Art
In recent years, communication apparatuses that perform contactless communication, such as contactless type IC (Integrated Circuit) cards and RFID (Radio Frequency IDentification), have proliferated. Such communication apparatuses that perform contactless communication include one that produces magnetic field coupling and one that produces electric field coupling.
In the case of producing magnetic field coupling, a communication apparatus has, for example, an antenna coil and performs contactless communication by magnetic field coupling using an alternating-current magnetic field at the antenna coil. On the other hand, in the case of producing electric field coupling, a communication apparatus has, for example, a plate-like electric field coupling electrode (coupler) and performs contactless communication by electric field coupling using an electrostatic field or induction field generated by the electric field coupling electrode (see, for example, Japanese Patent Application Laid-Open No. 2008-99236). Such communication apparatuses are suitable for short-range contactless communication such as a short-range type. Communication apparatuses that can be used for the aforementioned contactless type IC cards, etc., are mounted on cards, portable devices, etc., and are thus formed to be slim and compact.